Thread-measuring mechanism for shoe-sewing machines



Dec. 30, 1930. o. L. LAWSON THREAD MEASURING MECHANISM FOR SHOE SEWING MACHINES Filed May 26 1926 2 Sheets-Sheet l Dec. 30, 1930. o. 1.. LAWSON 1,786,621

THREAD MEASURING MECHANISM FOR SHOE SEWING MACHINES 1 Filed May 1926 2 Sheets-Sheet 2 his ears.

EQE

PAE

OSCAR L. LAW'SON, T1 LYNN, MASSACI-IUSETTS, ASSIGNOPL, BY MESNE ASSEGNMENTS, TO UNITED SHOE MACEZINERY CORPORATION, 0E PATERSON, NEW JERSEY, A COR- roe-Arron or new art-seer THREAD-MEASURING MECHANISM FOR SHOE-SEWING MACHINES Application filed May 26,

hooked needle and a shuttle supplying a and re shuttle thread at the upper side of the work,

while at the under side of the work is a work supporting horn provided with a looper or whirl which supplies a cop or needle thread,

-- together with take-up and stitch setting mechanism to draw the needle loop over the shuttle and set the stitch.

The present invention relates particularly to mechanism, applicable to machines of the above and similar types, for controlling the cop or needle thread, and particularly for drawing the latter from the source of supply in measured quantities in accordance with the length of stitch and the thickness of the a work and for holding the same for the action of take-up and stitch setting mechanism. The primary ob ect of the lnvention is to provide improved thread measurlng and clamp ng mechanism which will correctt irrespective of the speed of operation of the machine, thereby permitting such a machine to be run at a higher speed than has heretoi'ore been possible in machines of this type.

The foregoing and other objects of the invention, together with means whereby the same may be carried into efiect, will best be understood from the following description of one term or embodiment'thereof illustrat ed in the accompanying drawings. It will be understood however that the particular construction described and shown has been chosen tor illustrative purposes merely, and that said invention, as defined by the claims hereunto appended, may be otherwise embodied withoutdeparture from the spirit and scope thereof.

In said drawings:

Fig. 1 is a side elevation, partly in secbly perform its intended functions 1926. S-Biial No. 111,859.

tion, of a substantially complete shoe sewing machine embodying the invention.

Figs. 2 and 3 are sections taken substantially on the lines 22 and 3-3, respectively, Fig. 1. I

Fig. 4 is a detail front elevation of the thread pull-cit member and thread clamps.

Fig. 5 is a detail section taken substantially on the line 55, Fig. 4t.

Fig. 6 is a similar view showing the parts in a different position. 7

In the embodiment of the invention shown, the frame of the machine comprises a hollow base carrying the work supporting horn l6 and from which rises a standard 17 carrying at its top the frame-work 18 of the head. The horn 16 is of a size and shape to render it capableoi' being inserted into the toe of a shoe and is mounted in a bearing 19 secured to the front oi the base 15 at the top of the latter. Said horn is provided with a ournal portion 20rotatably mounted in the bearing 19 in such a manner as to pe unit said horn to be turned as the sewing progresses. The nee dle 21, which is above the work A, is straight and is formed adjacent its pointed lower end with an open, loop-engaging hook, said needle being carried by a needle bar 22 guided for rectilinear reciprocating movement in the head 18. lVithinthe tip of the horn l6, and therefore below the work or at the opposite side thereof from the needle 21, is a whirl 23 which is rotatably mounted in said horn and is provided with an eccentric opening through which the cop or needle thread passes loosely, and with an axial opening to receive the point of the needle when the latter descends to penetrate the work, whereby said whirl operates to form a loop about the needle immediately above the hook of the latter. Thereafter, as the needle rises, the loop so formed is drawn upwardly through the work. Above the work, or at the same side thereof as the needle, is an oscillating discoidal shuttle 26 carrying a shuttle thread, said shuttle having a hook or beak adapted, when the ne dle rises, to receive the loop of needle thread from the needle hook and pass it about the shuttle and shuttle thread. The machine also includes, below the work, mechanism acting on the needle thread C to draw the needle loop over the shuttle and down upon the work, thereby completing); the formation of the st'tch, and thereafter to the latter by drawing the thread locks into the material. Said last named mechanism as ierein shown is of the type more fully described in another application filed May 26, 1926, Serial No. 111,861, and includes a combined take-up and h setter 2S guided in the horn 16, and c gr the needle taread C between two fixed thread guides 29. The combined take up an d ch setter 28 is connected to the free end of a lever 31 pivoted w hin the'base of thehorn to a bracket 14 ha a l ow eylin drical stem 13 which extends axially through the journal portion or the born. The lever 31 is connected intermediate its ends with a slide 32 passing eccentrically through the stem 13 of the bracket 14 and reciprocated therein by a lever 33 one end of which en gages an annular head 12 formed on the lower end of said slide. The needle thread is held for the action of the take-up 28 by a thread clamp 34, is drawn from the supply in measured quantities for each stitch by a combined thread pull-off and measurin device 35, and is also held for the action of the pullbff 35 by a second thread clamp 36, all hereinafter more fully described.

The needle bar 22 and shuttle 26 are actuated through suitable connections, not shown in detail. from a horizontally disposed main or power shaft 38 iournalled in the head 18 and receiving power from any suitable source through a pulley loosely mounted thereon and connected therewith by means of a clutch 4O operated through suitable connections by treadle lever 41 at the base of the machine. Connected, as by suiral gearing 42, with the shaft 38 is a vertical shaft 43 which extends downwardly alone or through the standard 17, is journalled at its lower end in a bracket 44 on the base 15, and carries a cam 45 for actuating the take-up lever 38.

The whirl is operated by mechanism which as herein shown is of the type more fully disclosed in another application filed May 26. 1926, Serial No. 111,860 and includes angularly disposed shafts 46 and 47 in the born 16, said shafts being connected with each other by gearing 48, the upper end of the shaft 46 being geared to the whirl 23, and the shaft 47 being connected by gearing 5O with a hollow vertical shaft 51 which extends axially through the stem 13 and carries a coaxial guide tube 11' for the thread (7. The shaft 51. is connected by rearing 53 with one end of a horizontal cam shaft 54 journalled in bearings on the base 15 and connected at its opposite end by gearing 55 with the vertical shaft 43.

During the formation and setting of each stitch the work A is clamped upon the born 16 by a presser foot 56 carried by a press-er i ecgesi foot bar 5? which is normally pressed uowu vardly by a spring 524 and is periodically raised to permit feeding of the worlr by instrumentalities not shown detail) by means of a bell-crank lever 58 actuated by a cam on the main shaft 38. The presse foot may also be manually raised to p t removal and insertion of the work by a lever engaging the presser f ot bar 57 and connect ed by a link 60 with a second lever 61 con- 1 cted by a link 62 witl a treadle lever 63 at it i base of the machine.

The thread measuring or pull-off member as comprises a rod guided for longitudinal movement in a bracket 64 secured to the ore terior of the base 15 and in a second bracl iii 72 within the latter, said rod having in its end a notch or slot (55 through which the needle thread C passes between two stationary thread hides in the form of alined openings 66 in a boss (3? formed on said bracket (34. The thread clamp 34 located between the i mll-ofl' membe 35 and the source of needle thread supply (not shown), while the thread clamp 36 is located between said pulloff member and the stitch-forming instrumentalities. Each of said threau clamps also comprises a rod guided for longitudinal movement in the brackets 64 and 72 and having a slot 68 through which the thread C passes, the slots 68 being; in alinement with the thread guides 66 and with the notch (35 in the pull-off member, whereby the thread may be led in a straight line through the mechanism, as shown in Fig. 4. Each thread clamp rod is provided with ahead, prefer-- ably in the form of a collar and .i "Ill. constituting the movable thread grippine' member adapted to camp the thread anal the face of the bracket (54, which constr i' e the cooperating stationary thread grip member, the rods being moved longitudinally to clamp or release the thread. Suitable Inca is are provided prevent turning of the rods 34 and 36 in the bracket 64, thereby preserving the alinement of the slots 68, said means as shown comprising guide pins Tl projecting from said bracket and engaging: notches in the collars I In operation, longitudinal movement of the pul -off member 35 from approximately the position shown in Fig. to approximately the position shown in F (5, with the thread clamp 34 open and the thread clamp 36 closed. causes the bottom of the notch to engage the thread C and deflect it out of its normal alinement between the guides 66, thereby drawing from the source of supply a length of thread whose amount depends upon the extent of such deflection. Thereafter. the thread clamp 34 is closed and the thread clamp 36 opened to permit the stitch-forming instrumentalities to tale up the thread so drawn off. In the embodiment of the invention herein illustrated, the lan e or amount of movement of the pull-oil member at each operation 1S constant, but the limits (i. e., the starting and stopping points) are automatically varied in accordance with the thickness of the worlr and are manually adusted in accordance with the length of stitch.

T he outward limit of movement of the pulloil, or movement toward the position shown in Fig. 6, determines the extent of deflection of the thread and consequently the amount drawn from the supply.

In the operation of thread measuring mechanism of the type employing a variably actuated pultoll member, as heretofore const-ructed, difficulty has been encountered in the tendency of the pull-oil member to over throw when the machine is speeded up, therey destroying the accuracy and consequently the utility of this mechanism, so that the speed of operation of the machine has been atinp' the pull-ofi member, and also for alter- 3 n nately operating the thread clamps in the sequencedescribed, is as follows Pivoted, as at 73 (Fig. 1), within the base 15, is a lever 74 having a. cam roller or follower 75 engaging a closed path in the periphery of a cam76 on the shaft Guided for longitudinal movement on the lever T l, that is to say, for movement in a direction transverse to the direction of movement of said lever, is a slide 7 7, said slide as shown 11- ring slots 78 engaged by studs 7 9 projectn from said lever. The slide 77 is connected by a link 80 with one end of a lever 81 pivoted at 82 to the head 18 and connected at its opposite end with the Presser-foot bar 57. T he slide 77 is formed with an inclined groove 88 which is engaged by a stud or projection 84 (see also Fig. 2) on a slide 85 guided for longitudinal movement on the rod but normally fired thereon.

When the lever 74 is oscillated on its pivot T3 by the cam 76, the rod or thread pull-otl' member is reciprocated to draw oil and release the thread, as above described. The slide 7?, with its inclined groove 83 engaged by the projection 84 on the rod 35, constitutes the operative connection between said rod and the lever T l. By reason or" the inclination of thegroove 83, the limits of movement of the rod 35, and consequently the amount of thread drawn from the supply, are determined by the position of the slide 77 on the lever 74;, which position is automatically controlled in accordance with the thickness of the wor: by its connection with the presser foot or work en aging member 56 through the presser foot bar 57, lever 81, and link 80. It will be seen that the pull-ed rod is positively actuated in both directions and that, by reason of the engagement of the cam follower 75 in the closed path of the cam 76 and the permanent engagement of the stud 8a in the groove 83, said rod is at all times under the positive control of its actuating means, so that overthrow there of is prevented irrespective of the speed of operation of the machine.

iThe lim ts of movement of the thread pull-oil member may also be manually adjusted in accordance with the length of stitch by varying the position of the slide 85 on the rod 35. To this end, said slide 'is in threaded engagement with an adjusting screw 86 (see Fig. 2) having a head 87 which engages a peripheralgroove 88 in a head 89 formed on the rod 35, thereby providing a micrometer adjustment which permits the setting of the parts with great accuracy.

The thread clampsare closed by springs 90 surrounding the rods 34 and 36 and interposed between the t'ront wall of the base 15 and collars 91 fast on said rods. Said thread clamps are opened to releasethe thread by means of a rocker 92 carrying abutment screws 93 and movable in opposite directions to bring said abutment screws into operative engagement with the ends of the rods 34 and 36 alternatively and move the same in opposition to the springs 90. The rocker 92 is carried by a shaft 94 3) journalled in the bracket 7:2 and having an arm 95 carrying a cam roller or follower '96 which engages a path inthe periphery of a cam 97 on the shaft 54.

It will be seen that, in addition to the advantages above pointed out, the mechanism described is very simple and compactly arranged, the single shaft in the base 15 being employed to actuate the whirl, the thread pull-oil member, and the thread clamps.

Having thus described my invention, I claim:

1. In a shoe-sewing machine, in combination, a work-engaging member, a thread pull-oil member, an actuator, and a slide guided on said actuator for movement in a direction transverse to the direction of movement of the latter and operatively connected with said work-engaging member, said slide having an inclined groove, and said pull-oil membed having a projection engaging said groove.

2. in a shoe-sewing machine, in combination, awork-engaging member, a thread pull oil member, a cam having a closed path, a lever having a cam follower in said path, and

a slide guided on said. lever for movement longitudinally thereof and operatively connected with said work-engaging member, said slide having an inclined groove, and said pull-oil member having a projection engaging groove.

3. In a shoe-sewing machine, in combination, a constant throw thread measuring memher, an actuator therefor, and means including a. micrometer adjustment for operatively connecting said member and actuator and varying the limits of" movement of said memher.

i:- In a shoe-sewing machine, in comliimn tion, a thread measuring plunger, an actuator therefor having a. groove, a slide guided on said plunger and having a stud engaging said groove, and an adjusting screw connecting said slide and plunger.

5. In a shoe machine, in combination, sewing devices including a hook needle, a thread pull'off member comprising a plunger to engage the thread, means for imparting a constant positive lengthwise reciprocating motion to the plunger in each direction, and means for varying the limits of movement of the plunger to vary the effective pulling-ctr action of the plunger on the thread.

6. In a shoe machine, in combination, sewing devices including a hook needle, a work supporting horn, a whirl contained within the horn, a thread pull-oft member comprising a plunger to engage the thread, means for guiding the thread at each side of the plunger, constant throw actuating mechanism for imparting a. positive lengthwise reciprocating movement to the plunger in each direction, and an adjustable connection between said actuating mechanism and the plunger to vary the limits of movement of the plunger to regulate the amount of thread pulled oil in accordance with the thickness of the worl 7. In a. shoe machine, in combination, sewing devices including ahoolc needle, a work supporting horn, a whirl contained within the horn, a thread pull-off member comprising a plunger to engage the thread, means for guiding the thread at each side of the plunger, a constant throw actuating mechanism for imparting a positive lengthwise reciprocating movement to the plunger in each direction, an adjustable connection between Said actuating means and the plunger to vary the limits of movement of the plunger to regulate the amount of thread pulled off in accordance with the thickness of the work, and an adjusting means between the plunger and said adjustable connection.

8. In a sewing machine, in combination, a thread measuring reciprocating plunger to engage the thread, an actuator therefor adapted to impart a constant throw to said plunger, and means for operatively connect- OSCAR L. LiU/VSON.

iii 

